Researchers say that a space rock that landed in Costa Rica on April 23rd, 2019, came from an asteroid that exists as a remnant of the early solar system. As such, they say that the rock is likely packed with complex carbon compounds, perhaps including amino acids, known as the building blocks of life that come together to make proteins and DNA.
While most other rocks from the early solar system eventually clustered together to become planets, this one seems to have remained intact. Over time, sunlight driven chemical reactions then led to the creation of increasingly complex carbon compounds.
While studies of this new meteorite, known as ‘Aguas Zarcas’, are incomplete, researchers are excited to use modern techniques to examine it in search of complex organic compounds. However, if found, this would not be the first space rock to contain these life building blocks.
In 1969, a meteor that exploded over Murchison, Australia had amino acids in its clay- a discovery that encouraged the idea that life on Earth may have come from chemicals delivered by meteorites. And so far, it seems that Aguas Zarcas has a similar profile, especially given that it seems to also contain dust from the ancient, earlier Milky Way- from even before our sun was formed.
While the shards from the Aguas Zarcas may be the most pristine samples of the early system we yet to have been discovered, the researchers say there is still a possibility that they were contaminated as they landed in a rainforest.
Soon, though, we may have even more pristine examples of early space rocks. For example, the Japanese Hayabusa2 probe is already on its way back to Earth, carrying dust from the asteroid Ryugu. Moreover, NASA is scheduled to return samples from Bennu, a similar asteroid. Unlike Aguas Zarcas, both of these samples will be ‘truly pristine’, having neither touched the Earth’s atmosphere nor rainforest soil.